ct90...k1

picked one up today, wasnt going to after i saw the rough condition, but a titled bike complete (less side covers) for 125$
how could i say no?!
my big dilema is rust....er well rot. the frame area under the gas tank is swiss cheese.
its actually the "under rear fender" area of the bike. strange spot but im not sure if i should weld some sheet metal in there or part the bike out and use the motor on one of my st90 projects. i was going to go lifan 125 or 140 for the st90 bikes but neither have titles and i really like the ct, always wanted one. this one is just a bit more of a project than i wanted.
but i have the sickness.the rest of the bike is solid. beat up and ugly but solid. hmmm.
what makes the k1 special? the plastics are different but i cant see much else. gonna clean her up and see if she runs i guess. has original keys, been in a shed for 8 years. damn. i dont have time for this! anyone wanna swap thier ct90/110 rider for a complete st90 and ct90? theyre both yellow...thats all ive got.
slams?encouragement wanted...

thanks for the replies guys, i went through the carb. it wasnt bad at all, the jets were clean. so thats good, mouse nest in the air filter and the chewed threw the boot. no spark though, going to clean her up, get her running and make a decision from there. the welding and fabrication i can handle, just a matter of no time for toys.
lubed up the cables...hopefully spend some time on it soon and then choose between the ct or the st. too many projects and not enough time.
looking foward to it though.
i think i read somewhere that the 69 had a hotter cam. is this correct?

Dont know if you know but you need a good charged battery to get spark. No battery no spark

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thanks yz, i figured the battery from 1982 that was in there, with its 3. something volts would still complete the circuit giving me something? i spent a half hour doing some cleaning up and pecking around and the mousepricks ate my wires! i hate those lil bastards. stopped at the battery shop and paid a whopping 10 bucks for a nice agm 5ah battery that looks like it will fit the bill. now to pull it apart and find the coil... is it hiding way up under the fuel tank? thats where im finding my chewed up wires. and the rot i think was caused by rat piss. oh well.

If your here you have likely also found the CT 90 CT 110 group they have been very helpful in sorting out gremlins in my 71 CT 90. Some pics would be great if you can post some. I thought mine may have been iffy and I bought it for $325. I spent another $350 getting the Carb Cleaned, new tires and tubs, points and plugs, and a new Battery. That got it fired up. Then it needed a valve adjustment and the plugs needed to be correctly gapped. Someone said that half the fun was riding them and the other half tinkering on them. I feel like I have brought back to service an otherwise neglected fine motorbike.
Keep up the good work. I'm interested in your progress.

windburn- sorry on the pics, no extra loot for the smugmug.
offcenter, thanks, i joined that last week.
motorandy, amazon has a lifan 125 for 200 bucks! and check out the seat from a honda urban express, im sure it will need mods to fit, but i always thought that seat would go good on a ct!
today im going to finish a full tune up, set valves and points... and try to fire her up! cross your fingers for me...
oh yeah, my wife and i have our own little bike club called the"danger squad"
she set it up on myspace years ago, we just terrorize around town on little (under125 bikes-her rules) illegal bikes (no lights,plates... only once did she get stopped by the man who made her walk a ct70 home!

my wife and i have our own little bike club called the"danger squad"
she set it up on myspace years ago, we just terrorize around town on little (under125 bikes-her rules) illegal bikes (no lights,plates...

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Now that sounds like fun. I kinda resemble that as im rockin a moped sticker on mine right now (vs plate as its over 50cc)

Now that sounds like fun. I kinda resemble that as im rockin a moped sticker on mine right now (vs plate as its over 50cc)

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alright alright ill hafta get that going...
and for the record, we tried to do it legit, but the registry said that there are so many little bikes around that this, a ct70 was considered a moped. abide by the moped laws and keep the paper from the registry on the bike. that ct70 will do about 50mph! (upgraded a little bit)

soooo i set the valves, i think they were at -.004 little too tight.
the points were new looking but as out as they could get, and i didnt have a good light with me so i set them with a peice of paper for now...
the po said its been in the shed for 8 years! and by the smell of the gas i beleive it, anyway shes a runner.
took some kicking and fiddling but i got her to putt around. this is interesting though- it will only run with the lights on.
the off position is a kill switch! kinda cool? gonna hafta look into that.
so next up is a tank drain/flush/super reclean the carb and new fuel lines and plug. get the timing spot on. cam chain is a bit noisy as well so ill get to that.
then the big decide.
keep her and ride her tires off, probly a lifan cantidate. or sell her off to fund an st90 project...

That Urban Seat looks cool! These bikes have a tricky electrical system. The battery is the regulator. On some the lights come off a separate winding and a resistor is switched in when the light is off (as the load helps to regulate the voltage). So maybe your resistor is bad or the switch doesn't work right? Be careful as a bad setup will blow the lights (and they're all 6V!).

i just picked up a "sdg" 124cc 3 valve motor! it looks like a nice piece. as far as china motors go anyhow.
i have to spend a bit of time on the wiring and such but its a strong lil beast.
so the 69 ct90 will get the transformation, guy down the road has a kdx80 front end for 20 buck so i my try and work that in there.
now to decide on the 90 motor...should i put it on the st90? or sell it to buy a lifan...decisions

One of the bummers about an old CT is that the forks are usually rusty as hell under the rubber boots and headlight ears. A vendor on eBay is selling internal spring replacements for $73.59 (plus $19.99 shipping) that are a direct bolt-on replacement for the worn-out forks that are likely on the CT in your garage. The nice thing about them is you have the choice of running the boots (or not) since the external springs are eliminated.

They're sold by "ophir4u" and the item number is 190781758091.

A set of replacement chrome tubes from Forking by Frank cost $250 so you can see what a tremendous buy these are. I bought a set and I'm very happy with 'em.

Not really. They're pretty much just a replacement but at least they're oil tight unlike trying to rebuild a set of forks with rusty, pitted tubes. I think the biggest advantage is that the springs are internal rather than external as on the stockers. You can still use the stock boots and headlight ears and unless somebody pulled up the boots and looked no one would know they're not stock. Another vendor on eBay sells CT-90 fork rebuild kits with the boots and such. Buying a rebuild kit and the replacement forks is still way cheaper than rebuilding the stockers if your time is worth anything.

Improving their action would be a matter of heavier fork oil, welding up and redrilling the dampener holes and trying to find stiffer springs. We're definitely not talking cartridge forks here...

Something off of an 80 moto-bike would be cool but the problem is you'd end up with a chopper looking thing with the front suspension way out of balance from the rear. You could have someone make some spacers to install under the damper rods to shorten the forks which would require either finding some shorter springs or wacking them to size.

I initially set up my my CT-200 based bike with an XR-100 front end and a Passport swingarm w/13+" shocks to balance out the bike. It sits a little high for my munchkin legs, though so I bought a set of XR-80 forks (2" shorter) and will try it with those fork legs and either replace the 13" shocks with stock Passport units or install a CT-90 swingarm and use the shocks I have on it now which will basically give it a stock ride height.

With the XR-100 forks, Passport swingarm and 13" shocks it puts some daylight between the rear tire and fender which looks pretty cool. Angling the swingarm like that does funny things to chain adjustment just like what happened back when dirt bikes first started moving the shocks forward in the early '70's for more travel. I put an XR-100 chain slider on the swingarm to keep the chain from sawing a hole in the crossmember and with the limited travel of the shocks I'm hoping keeping the proper tension on the chain with that setup won't be a problem. We'll see.

Side note--to use XR-80/100 forks on the CT/Passport chassis you have to lengthen the steering stem. I sawed mine in two, turned a plug on the lathe to match the I. D. of the steering stem and had it heliarc'ed in place.